how dry does wood need to be....

[newbie69]

Hi, I wonder if you can help - I'm very new to using wood. I want to make some small sculptures using blocks of wood - the sort of thing someone might put on their mantlepiece. How dry the wood needs to be so...
1. it's stable
2. won't cause any problems if someone put one e.g. on their antique wooded sideboard (I guess if the wood's really green still it could mark the surface?)

Thank you

 

[custard]

On top of a mantlepiece could be the driest location in a home. To reduce the risk of cracking and splitting you'd need especially dry timber, I doubt any air dried timber would ever get that dry. You need kilned wood, but kilned wood is a bit harder to carve, so I suggest you get yourself a block of relatively easily worked timber like Lime which is widely available in sizes specifically for carving.

Really wet wood doesn't just leech water (which in itself will stain many furniture finishes from oiled to French polished), it also releases a pot pourri of other chemicals from tannins to oils. To be safe I wouldn't put any green wood on a polished surface. Dry the sculpture then possibly think about gluing felt to the base?

Good luck!

 

[newbie69]

Thanks Custard, much appreciated, I'll look for kiln-dried wood....
You suggest drying the sculpture - how would I dry wood myself?

I've bought a moisture-meter now... please does anyone have advice on what % counts as dry?

Thanks again

 

[woodfarmer]

wood is stable until its moisture content changes. this could mean getting drier OR wetter. so for it to be stable it has to be at the ambient moisture level. Sad thing is, this often varies so it is always likely to move a bit. Maybe ok in a sealed Egyptian pyramid.

Just have to accept it is a natural dynamic material/

 

[John15]

With your moisture meter check a few items of wooden furniture in the house. This will give you a good idea what to aim at.

John

 

[CHJ]

Around 10-12% should be OK in the average home situation, if you put it on a sunlit windowsill or near a radiator then it could show cracks/splits.

If you have blocks of locally acquired wood in the 20-30% range then put them in a paper bag or wrap in newspaper and place somewhere sheltered from extremes until they reduce to 10-12 %. Wrapping is to endeavour to provide a micro climate around the piece so that the surface will not dry out too rapidly, giving the internal moisture time to migrate outwards.

If they are small at this stage you may get away with gently heating them in a microwave in short bursts, until warm, not hot, allowing to cool between bursts until reading drops below 8%.
Wait a day to check this figure to see if more moisture migrates out.

Alternate place the pieces in the plate warming oven when the cooker is in use or the slow oven in an Aga.

 

[newbie69]

Thank's great, thank you very much.

 

[custard]

I've bought a moisture-meter now... please does anyone have advice on what % counts as dry?

The HMSO Handbook Of Hardwoods (now unfortunately out of print), quotes Lime as having a natural moisture content of 11.5% when kept in an environment with 60% relative humidity (which would roughly approximate to an average indoors environment, probably dropping a bit lower with the central heating blasting out). So if your Lime was down to 10-12% then you're good to go!

Other names for this wood, or related species, are Basswood and Linden. All very suitable for carving. In fact it's generally thought that it was the move from Oak to Lime that was responsible for the creative explosion in woodcarving that occurred in the 17th Century, culminating in the work of Grinling Gibbons. So, stick with Lime and you're in good company!

You can get it ready kilned from lots of sources, here's just one,

http://www.slhardwoods.co.uk/products/c ... ing-blanks

Normally I'm a strong proponent of getting down to a timber yard and personally inspecting wood before buying. But Lime is so homogenous and consistent that I'd happily buy it sight unseen by mail order.

Good luck!

 

[newbie69]

Thank you

 

[HOJ]

the work of Grinling Gibbons

I borrowed a book from the library, years ago, brilliant, I recomend any one wishing to learn carving!, read up on him.